U.S. patent application number 14/447222 was filed with the patent office on 2015-08-20 for vibration generating apparatus.
This patent application is currently assigned to SAMSUNG ELECTRO-MECHANICS CO., LTD.. The applicant listed for this patent is SAMSUNG ELECTRO-MECHANICS CO., LTD.. Invention is credited to Joon Choi, Jee Kyung Kim, Sang Jin Lee, Dong Su Moon, Kyung Su Park, Yeon Ho Son.
Application Number | 20150236241 14/447222 |
Document ID | / |
Family ID | 53798881 |
Filed Date | 2015-08-20 |
United States Patent
Application |
20150236241 |
Kind Code |
A1 |
Moon; Dong Su ; et
al. |
August 20, 2015 |
VIBRATION GENERATING APPARATUS
Abstract
There is provided a vibration generating apparatus including: an
elastic member having both end portions thereof fixedly installed
on a support part of a lower case; a piezoelectric element
installed on one surface of the elastic member; and a mass body
part connected to the elastic member to increase an amount of
vibrations, wherein the mass body part is provided with protrusion
portions for first contacting the lower case at the time of an
external impact.
Inventors: |
Moon; Dong Su; (Suwon-Si,
KR) ; Park; Kyung Su; (Suwon-Si, KR) ; Lee;
Sang Jin; (Suwon-Si, KR) ; Kim; Jee Kyung;
(Suwon-Si, KR) ; Choi; Joon; (Suwon-Si, KR)
; Son; Yeon Ho; (Suwon-Si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRO-MECHANICS CO., LTD. |
Suwon-Si |
|
KR |
|
|
Assignee: |
SAMSUNG ELECTRO-MECHANICS CO.,
LTD.
Suwon-Si
KR
|
Family ID: |
53798881 |
Appl. No.: |
14/447222 |
Filed: |
July 30, 2014 |
Current U.S.
Class: |
310/323.01 |
Current CPC
Class: |
H01L 41/0933 20130101;
H01L 41/053 20130101; B06B 1/12 20130101 |
International
Class: |
H01L 41/09 20060101
H01L041/09 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2014 |
KR |
10-2014-0017925 |
Claims
1. A vibration generating apparatus comprising: an elastic member
having both end portions thereof fixedly installed on a support
part of a lower case; a piezoelectric element installed on one
surface of the elastic member; and a mass body part connected to
the elastic member to increase an amount of vibrations, wherein the
mass body part is provided with protrusion portions for first
contacting the lower case at the time of an external impact.
2. The vibration generating apparatus of claim 1, wherein the mass
body part includes a mass body case connected to the piezoelectric
element through an adhesive member and a mass body installed in the
mass body case, and the protrusion portions are provided on the
mass body case.
3. The vibration generating apparatus of claim 2, wherein the
protrusion portions are extended downwardly from both side surfaces
of the mass body case, respectively, and are disposed at a central
portion of the mass body case in a length direction thereof.
4. The vibration generating apparatus of claim 2, wherein the
protrusion portions are extended downwardly from both side surfaces
of the mass body case, respectively, and are disposed so as to be
provided adjacently to both end portions thereof of the mass body
case in a length direction thereof, respectively.
5. The vibration generating apparatus of claim 3, wherein distal
ends of the protrusion portions are disposed below a damper member
installed on a lower surface of the elastic member.
6. The vibration generating apparatus of claim 2, wherein the
adhesive member is formed of a soft material.
7. The vibration generating apparatus of claim 6, wherein the
adhesive member is formed of tape containing a rubber
component.
8. The vibration generating apparatus of claim 1, wherein the
protrusion portion has a polygonal shape when viewed from a
front.
9. The vibration generating apparatus of claim 2, wherein the
protrusion portions include first and second protrusions disposed
so as to be spaced apart from a center line of the mass body case
by a predetermined interval and third and fourth protrusions
disposed so as to be spaced apart from the first and second
protrusions, respectively, in a length direction.
10. The vibration generating apparatus of claim 9, wherein the
third and fourth protrusions are disposed at both end portions
thereof of the mass body case, respectively.
11. The vibration generating apparatus of claim 9, wherein the
first and second protrusions have sizes larger than those of the
third and fourth protrusions.
12. The vibration generating apparatus of claim 9, wherein the mass
body case is provided with a groove into which the piezoelectric
element is inserted.
13. The vibration generating apparatus of claim 2, wherein the mass
body case is provided with bonding protrusions for increasing
coupling force between the mass body case and the mass body, and
the mass body is provided with bonding grooves into which the
bonding protrusions are inserted.
14. A vibration generating apparatus comprising: an elastic member
having both end portions thereof fixedly installed on a support
part of a lower case; a piezoelectric element installed on one
surface of the elastic member; a mass body case connected to the
piezoelectric element through an adhesive member; and a mass body
installed in the mass body case, wherein the mass body case is
provided with protrusion portions extended downwardly from both
side surfaces of the mass body case, respectively.
15. The vibration generating apparatus of claim 9, wherein distal
ends of the protrusion portions are disposed below a damper member
installed on a lower surface of the elastic member.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent
Application No. 10-2014-0017925 filed on 17 Feb., 2014, with the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] The present disclosure relates to a vibration generating
apparatus.
[0003] Such a vibration generating apparatus, converting electrical
energy into mechanical vibrations using the principle of the
generation of electromagnetic force, has commonly been mounted in
mobile phones, and the like, to thereby be used for silently
notifying a user of call reception by transferring vibrations
thereto. In addition, in accordance with the rapid growth in the
market for mobile devices such as the mobile phone, and the like,
and the trend for the addition of added functionality to mobile
devices, the mobile devices have been required to be relatively
small in terms of size while having high quality. In this
situation, the demand for the development of a vibration generating
apparatus having a novel structure capable of overcoming the
disadvantages of existing vibration generating apparatuses and
having significantly improved quality has increased.
[0004] Further, as the release of smartphones, among mobile phones,
has rapidly increased, a touchscreen user interface scheme has been
adopted for use therein, such that a vibration motor has been used
in order to generate vibrations at the time of a touch interaction
with a touchscreen. Levels of performance required in the
vibrations generated at the time of a touch interaction with such a
touchscreen are as follows. First, since the amount of vibrations
generated by a vibration generation apparatus is greater in the
case of vibrations generated in response to a touch interaction
with a touchscreen than in the case of vibrations generated at the
time of call reception, the operational lifespan of a vibration
generation apparatus should be extended. Second, in order to raise
user's satisfaction when a user feels the vibrations at the time of
touching the touchscreen, a response speed of the vibrations should
increase in accordance with a touch speed of the touchscreen.
[0005] A piezo haptic actuator has been used as a product capable
of implementing such features. Such a piezo haptic actuator uses
the principle of an inverse piezoelectric effect in which
displacement is generated when a voltage is applied to a piezo
element, that is, a principle of allowing the weight of a mass body
to be moved by the generated displacement to generate vibrational
force.
[0006] A vibrator having the above-mentioned structure has the
following features. A bandwidth of a frequency capable of obtaining
a predetermined level of vibrational force or more is wide, such
that stable vibration characteristics may be implemented, and
vibrations having high and low frequencies, rather than a single
frequency, within a predetermined frequency range may be variously
used. In addition, since the vibrator may implement rapid operation
response characteristics, it may be appropriate for implementing
haptic vibrations in a mobile device such as a mobile phone, or the
like.
[0007] However, the piezo element may be easily damaged due to
external impacts. In other words, in the case in which the piezo
element is disposed on a lower surface of an elastic plate of the
mass body, the piezo element may be easily damaged due to a contact
between the piezo element and a lower case when an external impact
is applied to the vibrator.
RELATED ART DOCUMENT
[0008] (Patent Document 1) Korea Patent Laid-Open Publication No.
2011-45486
SUMMARY
[0009] An aspect of the present disclosure may provide a vibration
generating apparatus capable of decreasing damage to a
piezoelectric element.
[0010] According to an aspect of the present disclosure, a
vibration generating apparatus may include: an elastic member
having both end portions thereof fixedly installed on a support
part of a lower case; a piezoelectric element installed on one
surface of the elastic member; and a mass body part connected to
the elastic member to increase an amount of vibrations, wherein the
mass body part is provided with protrusion portions for first
contacting the lower case at the time of an external impact.
[0011] The mass body part may include a mass body case connected to
the piezoelectric element through an adhesive member and a mass
body installed in the mass body case, and the protrusion portions
may be provided on the mass body case.
[0012] The protrusion portions may be extended downwardly from both
side surfaces of the mass body case, respectively, and be disposed
at a central portion of the mass body case in a length direction
thereof.
[0013] The protrusion portions may be extended downwardly from both
side surfaces of the mass body case, respectively, and be disposed
so as to be provided adjacently to both end portions thereof of the
mass body case in a length direction thereof, respectively.
[0014] Distal ends of the protrusion portions may be disposed below
a damper member installed on a lower surface of the elastic
member.
[0015] The adhesive member may be formed of a soft material.
[0016] The adhesive member may be formed of tape containing a
rubber component.
[0017] The protrusion portion may have a polygonal shape when
viewed from a front.
[0018] The protrusion portions may include first and second
protrusions disposed so as to be spaced apart from a center line of
the mass body case by a predetermined interval and third and fourth
protrusions disposed so as to be spaced apart from the first and
second protrusions, respectively, in a length direction.
[0019] The third and fourth protrusions may be disposed at both end
portions thereof of the mass body case, respectively.
[0020] The first and second protrusions may have sizes larger than
those of the third and fourth protrusions.
[0021] The mass body case may be provided with a groove into which
the piezoelectric element is inserted.
[0022] The mass body case may be provided with bonding protrusions
for increasing coupling force between the mass body case and the
mass body, and the mass body may be provided with bonding grooves
into which the bonding protrusions are inserted.
[0023] According to another aspect of the present disclosure, a
vibration generating apparatus may include: an elastic member
having both end portions thereof fixedly installed on a support
part of a lower case; a piezoelectric element installed on one
surface of the elastic member; a mass body case connected to the
piezoelectric element through an adhesive member; and a mass body
installed in the mass body case, wherein the mass body case is
provided with protrusion portions extended downwardly from both
side surfaces of the mass body case, respectively.
[0024] Distal ends of the protrusion portions may be disposed below
a damper member installed on a lower surface of the elastic
member.
BRIEF DESCRIPTION OF DRAWINGS
[0025] The above and other aspects, features and other advantages
of the present disclosure will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0026] FIG. 1 is a schematic cross-sectional view illustrating a
vibration generating apparatus according to an exemplary embodiment
of the present disclosure;
[0027] FIG. 2 is an exploded perspective view illustrating the
vibration generating apparatus according to an exemplary embodiment
of the present disclosure;
[0028] FIG. 3 is a schematic perspective view illustrating a mass
body part included in the vibration generating apparatus according
to an exemplary embodiment of the present disclosure;
[0029] FIG. 4 is a schematic cross-sectional view illustrating a
vibration generating apparatus according to another exemplary
embodiment of the present disclosure;
[0030] FIG. 5 is a schematic perspective view illustrating a mass
body part included in the vibration generating apparatus according
to another exemplary embodiment of the present disclosure;
[0031] FIG. 6 is a front view illustrating a first modified example
of the mass body;
[0032] FIG. 7 is a bottom perspective view illustrating the first
modified example of the mass body;
[0033] FIG. 8 is a front view illustrating a second modified
example of the mass body; and
[0034] FIG. 9 is a bottom perspective view illustrating a third
modified example of the mass body.
DETAILED DESCRIPTION
[0035] Hereinafter, embodiments of the present disclosure will be
described in detail with reference to the accompanying drawings.
The disclosure may, however, be embodied in many different forms
and should not be construed as being limited to the embodiments set
forth herein. Rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the disclosure to those skilled in the art. In the
drawings, the shapes and dimensions of elements may be exaggerated
for clarity, and the same reference numerals will be used
throughout to designate the same or like elements.
[0036] FIG. 1 is a schematic cross-sectional view illustrating a
vibration generating apparatus according to an exemplary embodiment
of the present disclosure; FIG. 2 is an exploded perspective view
illustrating the vibration generating apparatus according to an
exemplary embodiment of the present disclosure; and FIG. 3 is a
schematic perspective view illustrating a mass body part included
in the vibration generating apparatus according to an exemplary
embodiment of the present disclosure.
[0037] Referring to FIGS. 1 through 3, a vibration generating
apparatus 100 according to an exemplary embodiment of the present
disclosure may include a housing 110, an elastic member 120, a
piezoelectric element 130, a circuit board 140, and a mass body
part 150 by way of example.
[0038] The housing 110 may have a rectangular parallelepiped shape
and include an upper case 112 and a lower case 114. In addition, as
an example, the upper case 112 may have a box shape having an
internal space, and the lower case 114 may have a plate shape.
[0039] Meanwhile, the upper case 112 may have the box shape of
which a lower portion is opened, and the lower case 114 having the
plate shape may be assembled to a lower end portion of the upper
case 112.
[0040] In addition, the upper case 112 may have a groove in at
least one of both end surfaces thereof in order to withdraw the
circuit board 140. That is, one end portion of the circuit board
140 may be withdrawn through the groove 115 formed in the upper
case 112 when the upper case 112 and the lower case 114 are
assembled to each other.
[0041] The lower case 114 may have support parts 114a formed
thereon in order to support both end portions thereof of the
elastic member 120. As an example, the support parts 114a may be
formed by denting and may have a rectangular pillar shape.
[0042] In addition, the lower case 114 may have an extension plate
114b formed at one of both end portions thereof, wherein the
extension plate 114b is extended so as to protrude from the upper
case 112 in a length direction. The extension plate 114b may
provide a seating surface on which the withdrawn portion of the
circuit board 140 is seated at the time of withdrawing the circuit
board 140.
[0043] The elastic member 120 may have both end portions thereof
fixedly installed on the housing 110. Therefore, the elastic member
120 may have fixed ends formed at both end portions thereof.
Although the case in which the elastic member 120 is fixedly
installed on the lowercase 120 has been described by way of example
in the present exemplary embodiment, the present disclosure is not
limited thereto. That is, the elastic member 120 may be fixedly
installed on the upper case 112.
[0044] Meanwhile, the elastic member 120 may have an opening part
122 formed therein in order to electrically connect the
piezoelectric element 130 and the circuit board 140 to each other.
The opening part 122 may be formed in the elastic member 120 so
that one end portion of a lower surface of the piezoelectric device
130 may be exposed at the time of installing the piezoelectric
element 130.
[0045] That is, one end portion of the lower surface of the
piezoelectric element 130 may be exposed toward a lower portion of
the elastic member 120 by the opening part 122.
[0046] In addition, the opening part 122 may have, for example, a
rectangular shape when viewed from the top. However, a shape of the
opening part 122 is not limited thereto, but may be variously
changed.
[0047] The piezoelectric element 130 may be installed on the
elastic member 120 so as to face the mass body part 150. As an
example, the piezoelectric element 130 may be fixedly installed on
an upper surface of the elastic member 120. In addition, the
piezoelectric element 130 may have a plate shape with a rectangular
parallelepiped shape, and may include at least one pair of external
electrodes (not shown) formed on the lower surface thereof. The
external electrodes 132 may be positive (+) and negative (-)
electrodes.
[0048] The circuit board 140 may be installed beneath the elastic
member 120 so as to be connected to the piezoelectric element 130.
That is, the circuit board 140 may be installed on a lower surface
of the elastic member 120. In addition, the circuit board 140 may
have a connection electrode 142 formed thereon, wherein the
connection electrode 142 is inserted into the opening part 122
formed in the elastic member 120.
[0049] Meanwhile, the circuit board 140 may be a flexible printed
circuit board.
[0050] The mass body part 150 may be disposed above the
piezoelectric element 130 to increase an amount of vibrations of
the elastic member 120. Meanwhile, the mass body part 150 may
include amass body case 152 connected to the piezoelectric element
130 through an adhesive member 160 and a mass body 154 installed in
the mass body case 152.
[0051] The mass body case 152 may have the mass body 154 inserted
thereinto and have a lower surface connected to the piezoelectric
element 130 through the adhesive member 160.
[0052] Further, the mass body case 152 may be provided with
protrusion portions 156. The mass body case 152 will be described
in more detail. The mass body case 152 may include a bottom plate
152a supporting a lower surface of the mass body 154, side plates
152b extended upwardly from the bottom plate 152a and supporting
both side surfaces of the mass body 154, respectively, and
extension plates 152c extended from the side plates 152b,
respectively, in a width direction and supporting both end surfaces
of the mass body 154, respectively.
[0053] Meanwhile, here, terms with respect to directions will be
defined. In FIG. 2, a length direction refers to an X direction,
and a width direction refers to a Y direction. In addition, a
height direction refers to a Z direction. Further, the terms
defined above will be used below as the same meaning as the
above-mentioned meaning. That is, the above-mentioned terms with
respect to the respective components will indicate the same
directions as the above-mentioned directions.
[0054] In addition, side surfaces refer to two surfaces of the mass
body 154 opposing each other in the width direction, in other
words, surfaces having width areas, and end surfaces refer to two
surfaces of the mass body 150 opposing each other in the length
direction, in other words, distal end surfaces having areas
narrower than those of the side surfaces.
[0055] In addition, the protrusion portions 156 provided on the
mass body case 152 may be extended downwardly from the bottom plate
152a. Further, the protrusion portions 156 may be extended from a
central portion of the bottom plate 152a in the length direction
thereof.
[0056] In addition, distal end portions of the protrusion portions
156 may be disposed below a damper member 170 installed on the
lower surface of the elastic member 120 in order for the protrusion
portions 156 to first contact the lower case before the elastic
member 120 contacts the lower case at the time of an external
impact to allow external force not to be transferred to the
piezoelectric element 130.
[0057] In addition, the protrusion portion 156 may have a polygonal
shape when viewed from the front. As an example, the protrusion
portion 156 may have a rectangular shape as shown in the
accompanying drawings. However, the protrusion portion 156 is not
limited to having the above-mentioned shape. That is, a shape of a
lower surface of the protrusion portion 156 may be changed into
various shapes such as a wave shape, a rhombic shape, a sharp
shape, a round shape, and the like.
[0058] Further, the lower case 114 contacting the lower surface of
the protrusion portion 156 at the time of an external impact may
also be provided with a component capable of alleviating the
impact, such as a poron, a spring, an adhesive, or the like.
[0059] Meanwhile, the adhesive member 160 connecting the mass body
case 152 and the piezoelectric element 130 to each other may be
formed of a soft material, for example, tape containing a rubber
component.
[0060] In addition, the mass body 154 may be formed of a material
having a specific gravity, for example, tungsten, may serve to
amplify an amount of vibrations generated by deformation of the
piezoelectric element 130. Further, the mass body 154 may have a
shape corresponding to that of the mass body case 152 so as to be
installed in the mass body case 152.
[0061] Meanwhile, shapes of the mass body case 152 and the mass
body 154 are not limited to shapes shown in the accompanying
drawings, but may be variously changed.
[0062] In addition, although the case in which the protrusion
portion 156 is formed in the mass body case 152 has been described
by way of example in the present exemplary embodiment, the present
disclosure is not limited thereto. That is, the protrusion portion
156 may be formed in the mass body 154 and may protrude downwardly
of the mass body case 152.
[0063] As an example, in the case in which the mass body case 152
is omitted, the mass body 154 may be directly connected to the
piezoelectric element 130 through the adhesive member 160. In this
case, the protrusion portion 156 may be extended downwardly from a
central portion of the mass body 154.
[0064] As another example, in the case in which the mass body case
152 is not omitted, the protrusion portion 156 may also be extended
from the mass body 154.
[0065] As described above, since the protrusion portions 156 are
provided on the mass body case 152, a load transferred to the mass
body part 150 including the mass body case 152 at the time of the
external impact is not transferred to the elastic member 120 and
the piezoelectric element 130, but is directly transferred to the
housing 110 by the protrusion portions 156, whereby damage to the
piezoelectric element 130 may be decreased.
[0066] In other words, the mass body case 152 and the piezoelectric
element 130 may be connected to each other through the adhesive
member 160 formed of a soft material. Therefore, in the case in
which abnormal displacement occurs at the time of the external
impact, the load may be directly transferred to the mass body case
152 and be then transferred again to the housing 110, thereby
decreasing that the load due to the external impact is transferred
to the piezoelectric element 130 and the elastic member 120.
[0067] That is, the mass body part 150 and the piezoelectric
element 130 may be separately moved by the load due to the external
impact, thereby decreasing that the load transferred to the mass
body part 150 is transferred to the piezoelectric element 130.
[0068] As a result, the damage to the piezoelectric element 130 due
to the external impact may be decreased.
[0069] Hereinafter, a vibration generating apparatus according to
another exemplary embodiment of the present disclosure will be
described with reference to the accompanying drawings. However,
components the same as the above-mentioned components will be
denoted by the same reference numerals as the reference numerals
used in the above description, and a detailed description thereof
will be omitted.
[0070] FIG. 4 is a schematic cross-sectional view illustrating a
vibration generating apparatus according to another exemplary
embodiment of the present disclosure; and FIG. 5 is a schematic
perspective view illustrating a mass body part included in the
vibration generating apparatus according to another exemplary
embodiment of the present disclosure.
[0071] Referring to FIGS. 4 and 5, a vibration generating apparatus
200 according to another exemplary embodiment of the present
disclosure may include a housing 110, an elastic member 120, a
piezoelectric element 130, a circuit board 140, and a mass body
part 250 by way of example.
[0072] Meanwhile, since the housing 110, the elastic member 120,
the piezoelectric element 130, and the circuit board 140 are the
same as the housing 110, the elastic member 120, the piezoelectric
element 130, and the circuit board 140 of the vibration generating
apparatus 100 according to an exemplary embodiment of the present
disclosure described above, respectively, a detailed description
thereof will be omitted and replaced by the above description.
[0073] The mass body part 250 may be disposed above the
piezoelectric element 130 to increase an amount of vibrations of
the elastic member 120. Meanwhile, the mass body part 250 may
include amass body case 252 connected to the piezoelectric element
130 through an adhesive member 160 and a mass body 254 installed in
the mass body case 252.
[0074] The mass body case 252 may have the mass body 254 inserted
thereinto and have a lower surface connected to the piezoelectric
element 130 through the adhesive member 160.
[0075] Further, the mass body case 252 may be provided with
protrusion portions 256. The mass body case 252 will be described
in more detail. The mass body case 252 may include a bottom plate
252a supporting a lower surface of the mass body 254, side plates
252b extended upwardly from the bottom plate 252a and supporting
both side surfaces of the mass body 254, respectively, and
extension plates 252c extended from the side plates 252b,
respectively, in a width direction and supporting both end surfaces
of the mass body 254, respectively.
[0076] In addition, the protrusion portions 256 provided on the
mass body case 252 may be extended downwardly from the bottom plate
252a. Further, the protrusion portions 256 may be extended so as to
be provided adjacently to both end portions thereof of the bottom
plate 252a, respectively.
[0077] In addition, distal end portions of the protrusion portions
256 may be disposed below a damper member 170 installed on the
lower surface of the elastic member 120 in order for the protrusion
portions 256 to contact the lower case before the elastic member
120 contacts the lower case at the time of an external impact to
allow external force not to be transferred to the piezoelectric
element 130.
[0078] In addition, the protrusion portion 256 may have a polygonal
shape when viewed from the front. As an example, the protrusion
portion 256 may have a rectangular shape as shown in the
accompanying drawings. However, the protrusion portion 256 is not
limited to having the above-mentioned shape. That is, a shape of a
lower surface of the protrusion portion 256 may be changed into
various shapes such as a wave shape, a rhombic shape, a sharp
shape, a round shape, and the like.
[0079] Further, the lower case 114 contacting the lower surface of
the protrusion portion 256 at the time of an external impact may
also be provided with a component capable of alleviating the
impact, such as a poron, a spring, an adhesive, or the like.
[0080] Meanwhile, the adhesive member 160 connecting the mass body
case 252 and the piezoelectric element 130 to each other may be
formed of a soft material, for example, tape containing a rubber
component.
[0081] In addition, the mass body 254 may be formed of a material
having a specific gravity, for example, tungsten, may serve to
amplify an amount of vibrations generated by deformation of the
piezoelectric element 130. Further, the mass body 254 may have a
shape corresponding to that of the mass body case 252 so as to be
installed in the mass body case 252.
[0082] Meanwhile, shapes of the mass body case 252 and the mass
body 254 are not limited to shapes shown in the accompanying
drawings, but may be variously changed.
[0083] As described above, since the protrusion portions 256 are
provided on the mass body case 252, a load transferred to the mass
body part 250 including the mass body case 252 at the time of the
external impact is not transferred to the elastic member 120 and
the piezoelectric element 130, but is directly transferred to the
housing 110 by the protrusion portions 256, whereby damage to the
piezoelectric element 130 may be decreased.
[0084] In other words, the mass body case 252 and the piezoelectric
element 130 may be connected to each other through the adhesive
member 160 formed of a soft material. Therefore, in the case in
which abnormal displacement occurs at the time of the external
impact, the load may be directly transferred to the mass body case
252 and then transmitted to the housing 110, thereby decreasing the
amount of load due to the external impact being transferred to the
piezoelectric element 130 and the elastic member 120.
[0085] That is, the mass body part 250 and the piezoelectric
element 130 may be separately moved by the load due to the external
impact, thereby decreasing the load transferred to the mass body
part 250 being transferred to the piezoelectric element 130.
[0086] As a result, the damage to the piezoelectric element 130 due
to the external impact may be decreased.
[0087] Meanwhile, although the case in which the protrusion
portions 256 provided in the mass body part 250 are formed at both
sides, respectively, so as to be provided adjacently to both end
portions thereof, respectively, in the vibration generating
apparatus 200 according to another exemplary embodiment of the
present disclosure has been described by way of example, the
present disclosure is not limited thereto. That is, the protrusion
portions 256 may also be formed at all of both sides and a central
portion.
[0088] Hereinafter, modified examples of the mass body part will be
described with reference to the accompanying drawings.
[0089] FIG. 6 is a front view illustrating a first modified example
of the mass body; and FIG. 7 is a bottom perspective view
illustrating the first modified example of the mass body.
[0090] Referring to FIGS. 6 and 7, the mass body part 350 may
include a mass body case 352 and a mass body 354 adhered to and
installed on an upper surface of the mass body case 352.
[0091] Meanwhile, the mass body case 352 may be provided with
protrusion portions 356. The protrusion portions 356 may be formed
so as to be symmetrical to each other based on a center line C and
may be extended downwardly.
[0092] In addition, the protrusion portions 356 may include first
and second protrusions 356a and 356b disposed so as to be spaced
apart from the center line C by a predetermined interval in the
length direction and third and fourth protrusions 356c and 356d
disposed so as to be spaced apart from the first and second
protrusions 356a and 356b, respectively, by a predetermined
interval in the length direction.
[0093] In addition, sizes of the first and second protrusions 356a
and 356b may be larger than those of the third and fourth
protrusions 356c and 356d.
[0094] Meanwhile, the protrusion portions 356 may be provided at
both side surfaces of the mass body case 352, respectively.
[0095] In addition, the mass body case 352 may be provided with a
groove into which the piezoelectric element 130 (See FIG. 2) is
inserted.
[0096] FIG. 8 is a front view illustrating a second modified
example of the mass body; and FIG. 9 is a bottom perspective view
illustrating the third modified example of the mass body.
[0097] Referring to FIGS. 8 and 9, the mass body part 450 may
include a mass body case 452 and a mass body 454 assembled to the
mass body case 452.
[0098] Meanwhile, the mass body case 452 may be provided with
protrusion portions 456. The protrusion portions 456 may be formed
so as to be symmetrical to each other based on a center line C and
may be extended downwardly.
[0099] In addition, the protrusion portions 456 may include first
and second protrusions 456a and 456b disposed so as to be spaced
apart from the center line C by a predetermined interval in the
length direction and third and fourth protrusions 456c and 456d
disposed at both end portions thereof.
[0100] In addition, sizes of the first and second protrusions 456a
and 456b may be larger than those of the third and fourth
protrusions 456c and 456d.
[0101] Further, the mass body case 452 may be provided with bonding
protrusions 452a for increasing coupling force between the mass
body case 452 and the mass body 454. The bonding protrusions 452a
may be inserted into bonding grooves 454a formed in the mass body
454.
[0102] Meanwhile, the protrusion portions 456 may be provided at
both side surfaces of the mass body case 452, respectively.
[0103] In addition, the mass body case 452 may be provided with a
groove into which the piezoelectric element 130 (See FIG. 2) is
inserted.
[0104] As set forth above, according to exemplary embodiments of
the present disclosure, the mass body part may first contact a
lower bracket, whereby damage to the piezoelectric element may be
decreased.
[0105] While exemplary embodiments have been shown and described
above, it will be apparent to those skilled in the art that
modifications and variations could be made without departing from
the spirit and scope of the present disclosure as defined by the
appended claims.
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